Channel state information transmission

ABSTRACT

A wireless device receives control messages from a first base station. The control messages configure measurement parameters and triggers measurements of channel state information for a subset of carriers. The control messages configure an uplink transmission resource, physical uplink channel format, and a list of carriers. The wireless device measures and transmits the channel state information for each active carrier in the list of carriers. The wireless device simultaneously receives signals from a subset of carriers belonging to at least two base stations or belonging to at least two sectors of the first base station.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/538,683, filed Sep. 23, 2011, entitled “Channel State InformationTransmission,” which is hereby incorporated by reference in itsentirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present inventionare described herein with reference to the drawings, in which:

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present invention;

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers as per an aspect of an embodiment of the presentinvention;

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present invention;

FIG. 4 is a block diagram of a base station and a wireless device as peran aspect of an embodiment of the present invention;

FIG. 5 is a block diagram depicting a system for transmitting datatraffic over an OFDM radio system as per an aspect of an embodiment ofthe present invention;

FIG. 6 depicts an example flow chart for channel state informationtransmission in a wireless device as per an aspect of an embodiment ofthe present invention; and

FIG. 7 depicts an example flow chart for channel state informationtransmission in a wireless device as per an aspect of an embodiment ofthe present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present invention enable channel stateinformation transmission in wireless communication systems. Embodimentsof the technology disclosed herein may be employed in the technicalfield of wireless communication systems. More particularly, theembodiments of the technology disclosed herein may relate to enhancingchannel state information transmission in wireless communicationsystems.

Example embodiments of the invention may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CDMA (codedivision multiple access), OFDM (orthogonal frequency divisionmultiplexing), TDMA (time division multiple access), Wavelettechnologies, and/or the like. Hybrid transmission mechanisms such asTDMA/CDMA, and OFDM/CDMA may also be employed. Various modulationschemes may be applied for signal transmission in the physical layer.Examples of modulation schemes include, but are not limited to: phase,amplitude, code, a combination of these, and/or the like. An exampleradio transmission method may implement QAM (quadrature amplitudemodulation) using BPSK (binary phase shift keying), QPSK (quadraturephase shift keying), 16-QAM, 64-QAM, 256-QAM, and/or the like. Physicalradio transmission may be enhanced by dynamically or semi-dynamicallychanging the modulation and coding scheme depending on transmissionrequirements and radio conditions.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present invention. As illustrated in thisexample, arrow(s) in the diagram may depict a subcarrier in amulticarrier OFDM system. The OFDM system may use technology such asOFDM technology, SC-OFDM (single carrier-OFDM) technology, or the like.For example, arrow 101 shows a subcarrier transmitting informationsymbols. FIG. 1 is for illustration purposes, and a typical multicarrierOFDM system may include more subcarriers in a carrier. For example, thenumber of subcarriers in a carrier may be in the range of 10 to 10,000subcarriers. FIG. 1 shows two guard bands 106 and 107 in a transmissionband. As illustrated in FIG. 1, guard band 106 is between subcarriers103 and subcarriers 104. The example set of subcarriers A 102 includessubcarriers 103 and subcarriers 104. FIG. 1 also illustrates an exampleset of subcarriers B 105. As illustrated, there is no guard band betweenany two subcarriers in the example set of subcarriers B 105. Carriers ina multicarrier OFDM communication system may be contiguous carriers,non-contiguous carriers, or a combination of both contiguous andnon-contiguous carriers.

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers as per an aspect of an embodiment of the presentinvention. A multicarrier OFDM communication system may include one ormore carriers, for example, ranging from 1 to 10 carriers. Carrier A 204and carrier B 205 may have the same or different timing structures.Although FIG. 2 shows two synchronized carriers, carrier A 204 andcarrier B 205 may or may not be synchronized with each other. Differentradio frame structures may be supported for FDD (frequency divisionduplex) and TDD (time division duplex) duplex mechanisms. FIG. 2 showsan example FDD frame timing. Downlink and uplink transmissions may beorganized into radio frames 201. In this example, radio frame durationis 10 msec. Other frame durations, for example, in the range of 1 to 100msec may also be supported. In this example, each 10 ms radio frame 201may be divided into ten equally sized subframes 202. Other subframedurations such as including 0.5 msec, 1 msec, 2 msec, and 5 msec mayalso be supported. Sub-frame(s) may consist of two or more slots 206.For the example of FDD, 10 subframes may be available for downlinktransmission and 10 subframes may be available for uplink transmissionsin each 10 ms interval. Uplink and downlink transmissions may beseparated in the frequency domain. Slot(s) may include a plurality ofOFDM symbols 203. The number of OFDM symbols 203 in a slot 206 maydepend on the cyclic prefix length and subcarrier spacing.

In an example case of TDD, uplink and downlink transmissions may beseparated in the time domain. According to some of the various aspectsof embodiments, each 10 ms radio frame may include two half-frames of 5ms each. Half-frame(s) may include eight slots of length 0.5 ms andthree special fields: DwPTS (Downlink Pilot Time Slot), GP (GuardPeriod) and UpPTS (Uplink Pilot Time Slot). The length of DwPTS andUpPTS may be configurable subject to the total length of DwPTS, GP andUpPTS being equal to lms. Both 5 ms and 10 ms switch-point periodicitymay be supported. In an example, subframe 1 in all configurations andsubframe 6 in configurations with 5 ms switch-point periodicity mayinclude DwPTS, GP and UpPTS. Subframe 6 in configurations with 10 msswitch-point periodicity may include DwPTS. Other subframes may includetwo equally sized slots. For this TDD example, GP may be employed fordownlink to uplink transition. Other subframes/fields may be assignedfor either downlink or uplink transmission. Other frame structures inaddition to the above two frame structures may also be supported, forexample in one example embodiment the frame duration may be selecteddynamically based on the packet sizes.

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present invention. The resource grid structure intime 304 and frequency 305 is illustrated in FIG. 3. The quantity ofdownlink subcarriers or resource blocks (RB) (in this example 6 to 100RBs) may depend, at least in part, on the downlink transmissionbandwidth 306 configured in the cell. The smallest radio resource unitmay be called a resource element (e.g. 301). Resource elements may begrouped into resource blocks (e.g. 302). Resource blocks may be groupedinto larger radio resources called Resource Block Groups (RBG) (e.g.303). The transmitted signal in slot 206 may be described by one orseveral resource grids of a plurality of subcarriers and a plurality ofOFDM symbols. Resource blocks may be used to describe the mapping ofcertain physical channels to resource elements. Other pre-definedgroupings of physical resource elements may be implemented in the systemdepending on the radio technology. For example, 24 subcarriers may begrouped as a radio block for a duration of 5 msec.

Physical and virtual resource blocks may be defined. A physical resourceblock may be defined as N consecutive OFDM symbols in the time domainand M consecutive subcarriers in the frequency domain, wherein M and Nare integers. A physical resource block may include M×N resourceelements. In an illustrative example, a resource block may correspond toone slot in the time domain and 180 kHz in the frequency domain (for 15KHz subcarrier bandwidth and 12 subcarriers). A virtual resource blockmay be of the same size as a physical resource block. Various types ofvirtual resource blocks may be defined (e.g. virtual resource blocks oflocalized type and virtual resource blocks of distributed type). Forvarious types of virtual resource blocks, a pair of virtual resourceblocks over two slots in a subframe may be assigned together by a singlevirtual resource block number. Virtual resource blocks of localized typemay be mapped directly to physical resource blocks such that sequentialvirtual resource block k corresponds to physical resource block k.Alternatively, virtual resource blocks of distributed type may be mappedto physical resource blocks according to a predefined table or apredefined formula. Various configurations for radio resources may besupported under an OFDM framework, for example, a resource block may bedefined as including the subcarriers in the entire band for an allocatedtime duration.

According to some of the various aspects of embodiments, an antenna portmay be defined such that the channel over which a symbol on the antennaport is conveyed may be inferred from the channel over which anothersymbol on the same antenna port is conveyed. In some embodiments, theremay be one resource grid per antenna port. The set of antenna port(s)supported may depend on the reference signal configuration in the cell.Cell-specific reference signals may support a configuration of one, two,or four antenna port(s) and may be transmitted on antenna port(s) {0},{0, 1}, and {0, 1, 2, 3}, respectively. Multicast-broadcast referencesignals may be transmitted on antenna port 4. Wireless device-specificreference signals may be transmitted on antenna port(s) 5, 7, 8, or oneor several of ports {7, 8, 9, 10, 11, 12, 13, 14}. Positioning referencesignals may be transmitted on antenna port 6. Channel state information(CSI) reference signals may support a configuration of one, two, four oreight antenna port(s) and may be transmitted on antenna port(s) 15, {15,16}, {15, . . . , 18} and {15, . . . , 22}, respectively. Variousconfigurations for antenna configuration may be supported depending onthe number of antennas and the capability of the wireless devices andwireless base stations.

According to some embodiments, a radio resource framework using OFDMtechnology may be employed. Alternative embodiments may be implementedemploying other radio technologies. Example transmission mechanismsinclude, but are not limited to: CDMA, OFDM, TDMA, Wavelet technologies,and/or the like. Hybrid transmission mechanisms such as TDMA/CDMA, andOFDM/CDMA may also be employed.

FIG. 4 is an example block diagram of a base station 401 and a wirelessdevice 406, as per an aspect of an embodiment of the present invention.A communication network 400 may include at least one base station 401and at least one wireless device 406. The base station 401 may includeat least one communication interface 402, at least one processor 403,and at least one set of program code instructions 405 stored innon-transitory memory 404 and executable by the at least one processor403. The wireless device 406 may include at least one communicationinterface 407, at least one processor 408, and at least one set ofprogram code instructions 410 stored in non-transitory memory 409 andexecutable by the at least one processor 408. Communication interface402 in base station 401 may be configured to engage in communicationwith communication interface 407 in wireless device 406 via acommunication path that includes at least one wireless link 411.Wireless link 411 may be a bi-directional link. Communication interface407 in wireless device 406 may also be configured to engage in acommunication with communication interface 402 in base station 401. Basestation 401 and wireless device 406 may be configured to send andreceive data over wireless link 411 using multiple frequency carriers.According to some of the various aspects of embodiments, transceiver(s)may be employed. A transceiver is a device that includes both atransmitter and receiver. Transceivers may be employed in devices suchas wireless devices, base stations, relay nodes, and/or the like.Example embodiments for radio technology implemented in communicationinterface 402, 407 and wireless link 411 are illustrated are FIG. 1,FIG. 2, and FIG. 3. and associated text.

FIG. 5 is a block diagram depicting a system 500 for transmitting datatraffic generated by a wireless device 502 to a server 508 over amulticarrier OFDM radio according to one aspect of the illustrativeembodiments. The system 500 may include a Wireless CellularNetwork/Internet Network 507, which may function to provide connectivitybetween one or more wireless devices 502 (e.g., a cell phone, PDA(personal digital assistant), other wirelessly-equipped device, and/orthe like), one or more servers 508 (e.g. multimedia server, applicationservers, email servers, or database servers) and/or the like.

It should be understood, however, that this and other arrangementsdescribed herein are set forth for purposes of example only. As such,those skilled in the art will appreciate that other arrangements andother elements (e.g., machines, interfaces, functions, orders offunctions, etc.) may be used instead, some elements may be added, andsome elements may be omitted altogether. Further, as in mosttelecommunications applications, those skilled in the art willappreciate that many of the elements described herein are functionalentities that may be implemented as discrete or distributed componentsor in conjunction with other components, and in any suitable combinationand location. Still further, various functions described herein as beingperformed by one or more entities may be carried out by hardware,firmware and/or software logic in combination with hardware. Forinstance, various functions may be carried out by a processor executinga set of machine language instructions stored in memory.

As shown, the access network may include a plurality of base stations503 . . . 504. Base station 503 . . . 504 of the access network mayfunction to transmit and receive RF (radio frequency) radiation 505 . .. 506 at one or more carrier frequencies, and the RF radiation mayprovide one or more air interfaces over which the wireless device 502may communicate with the base stations 503 . . . 504. The user 501 mayuse the wireless device (or UE: user equipment) to receive data traffic,such as one or more multimedia files, data files, pictures, video files,or voice mails, etc. The wireless device 502 may include applicationssuch as web email, email applications, upload and ftp applications, MMS(multimedia messaging system) applications, or file sharingapplications. In another example embodiment, the wireless device 502 mayautomatically send traffic to a server 508 without direct involvement ofa user. For example, consider a wireless camera with automatic uploadfeature, or a video camera uploading videos to the remote server 508, ora personal computer equipped with an application transmitting traffic toa remote server.

One or more base stations 503 . . . 504 may define a correspondingwireless coverage area. The RF radiation 505 . . . 506 of the basestations 503 . . . 504 may carry communications between the WirelessCellular Network/Internet Network 507 and access device 502 according toany of a variety of protocols. For example, RF radiation 505 . . . 506may carry communications according to WiMAX (Worldwide Interoperabilityfor Microwave Access e.g., IEEE 802.16), LTE (long term evolution),microwave, satellite, MMDS (Multichannel Multipoint DistributionService), Wi-Fi (e.g., IEEE 802.11), Bluetooth, infrared, and otherprotocols now known or later developed. The communication between thewireless device 502 and the server 508 may be enabled by any networkingand transport technology for example TCP/IP (transport controlprotocol/Internet protocol), RTP (real time protocol), RTCP (real timecontrol protocol), HTTP (Hypertext Transfer Protocol) or any othernetworking protocol.

According to some of the various aspects of embodiments, an LTE networkmay include many base stations, providing a user plane (PDCP: packetdata convergence protocol/RLC: radio link control/MAC: media accesscontrol/PHY: physical) and control plane (RRC: radio resource control)protocol terminations towards the wireless device. The base station(s)may be interconnected with other base station(s) by means of an X2interface. The base stations may also be connected by means of an S1interface to an EPC (Evolved Packet Core). For example, the basestations may be interconnected to the MME (Mobility Management Entity)by means of the S1-MME interface and to the Serving Gateway (S-GW) bymeans of the S1-U interface. The S1 interface may support a many-to-manyrelation between MMEs/Serving Gateways and base stations. A base stationmay include many sectors for example: 1, 2, 3, 4, or 6 sectors. A basestation may include many cells, for example, ranging from 1 to 50 cellsor more. A cell may be categorized, for example, as a primary cell orsecondary cell. When carrier aggregation is configured, a wirelessdevice may have one RRC connection with the network. At RRC connectionestablishment/re-establishment/handover, one serving cell may providethe NAS (non-access stratum) mobility information (e.g. TAI-trackingarea identifier), and at RRC connection re-establishment/handover, oneserving cell may provide the security input. This cell may be referredto as the Primary Cell (PCell). In the downlink, the carriercorresponding to the PCell may be the Downlink Primary Component Carrier(DL PCC), while in the uplink, it may be the Uplink Primary ComponentCarrier (UL PCC). Depending on wireless device capabilities, SecondaryCells (SCells) may be configured to form together with the PCell a setof serving cells. In the downlink, the carrier corresponding to an SCellmay be a Downlink Secondary Component Carrier (DL SCC), while in theuplink, it may be an Uplink Secondary Component Carrier (UL SCC). AnSCell may or may not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,is assigned a physical cell ID and a cell index. A carrier (downlink oruplink) belongs to only one cell, the cell ID or Cell index may alsoidentify the downlink carrier or uplink carrier of the cell (dependingon the context it is used). In the specification, cell ID may be equallyreferred to a carrier ID, and cell index may be referred to carrierindex. In implementation, the physical cell ID or cell index may beassigned to a cell. Cell ID may be determined using the synchronizationsignal transmitted on a downlink carrier. Cell index may be determinedusing RRC messages. For example, when the specification refers to afirst physical cell ID for a first downlink carrier, it may mean thefirst physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.When the specification indicates that a first carrier is activated, itequally means that the cell comprising the first carrier is activated.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in wireless device, base station, radio environment, network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, traffic load, initial systemset up, packet sizes, traffic characteristics, a combination of theabove, and/or the like. When the one or more criteria are met, theexample embodiments may be applied. Therefore, it may be possible toimplement example embodiments that selectively implement disclosedprotocols.

Coordinated multi-point (CoMP) transmission/reception may be consideredfor LTE-Advanced as a tool to improve the coverage of high data rates,the cell-edge throughput and/or to increase system throughput. Downlinkcoordinated multi-point transmission (CoMP) is a relatively general termreferring to different types of coordination in the downlinktransmission from multiple geographically separated transmission points(TP). This includes coordination in the scheduling, including anybeam-forming functionality, between geographically separatedtransmission points and joint transmission from geographically separatedtransmissions points.

Downlink coordinated multi-point transmission may include dynamiccoordination among multiple geographically separated transmissionpoints. In this context, a serving cell may be the cell transmittingPDCCH assignments (a single cell). There are various CoMP categoriesincluding Joint Processing (JP) and Coordinated Scheduling/Beamforming(CS/CB). In Joint Processing (JP) data may be available at each point inCoMP cooperating set. In Joint Transmission, there may be PDSCHtransmission from multiple points (part of or entire CoMP cooperatingset) at a time. Data to a single wireless device may be simultaneouslytransmitted from multiple transmission points, e.g. to (coherently ornon-coherently) improve the received signal quality and/or cancelactively interference for other wireless devices. dynamic cell selectionmay be applied, in which PDSCH transmission occurs from one point at atime (within CoMP cooperating set). In CoordinatedScheduling/Beamforming (CS/CB), data may be available at serving cell(data transmission from that point) but user scheduling/beamformingdecisions may be made with coordination among cells corresponding to theCoMP cooperating set.

According to some of the various aspects of embodiments, there may bevarious CoMP sets including CoMP cooperating set and CoMP measurementset. CoMP cooperating set is a Set of (possibly geographicallyseparated) points directly or indirectly participating in PDSCHtransmission to wireless device. This set may or may not be transparentto the wireless device. CoMP transmission point(s) are a point or set ofpoints actively transmitting PDSCH to wireless device. CoMP transmissionpoint(s) may be a subset of the CoMP cooperating set. For Jointtransmission, the CoMP transmission points may be the points in the CoMPcooperating set. For dynamic cell selection, a single point may be thetransmission point at every subframe. This transmission point can changedynamically within the CoMP cooperating set. For coordinatedscheduling/beamforming, the CoMP transmission point may correspond tothe serving cell. CoMP measurement set may be the set of cells aboutwhich channel state/statistical information related to their link to thewireless device is reported as discussed. The CoMP measurement set maybe the same as the CoMP cooperating set. The actual wireless devicereports may down-select cells for which actual feedback information istransmitted (reported cells). RRM (radio resource management)measurement set may be defined in support of RRM measurements and maynot be CoMP specific.

Downlink coordinated multi-point transmission may include thepossibility of coordination between different cells. From aradio-interface perspective, the cells may belong to the same basestation or different base stations. If inter-base station coordinationis supported, information needs to be signaled between base stations.Potential impact on the radio-interface may include these areas:feedback and measurement mechanisms from the wireless device,preprocessing schemes, and reference signal design. Reporting of dynamicchannel conditions between the multiple transmission points and thewireless device may be required. For TDD, channel reciprocity may beexploited. Reporting to facilitate the decision on the set ofparticipating transmission points may be needed. For TDD, channelreciprocity may be exploited. Preprocessing schemes may include jointprocessing prior to transmission of the signal over the multipletransmission points. Downlink control signaling may support varioustransmission schemes. New forms of feedback and signaling may be neededto support CoMP that are, for example, configured by RRC for a givenwireless device. As baseline, the network may not need explicitly signalto the wireless device the CoMP transmission point(s) and the wirelessdevice reception/demodulation of CoMP transmissions (CS/CB, or JP withMBSFN subframes) may be the same as that for non CoMP (SU/MU-MIMO). Anyadditional feedback designed for CoMP may be consistent with thefeedback framework for SU/MU-MIMO.

According to some of the various aspects of embodiments, the three maincategories of CoMP feedback mechanisms may include explicit and implicitchannel state/statistical information feedback. Explicit channelstate/statistical information feedback may be channel as observed by thereceiver, without assuming any transmission or receiver processing.Implicit channel state/statistical information feedback may be feedbackmechanisms that use hypotheses of different transmission and/orreception processing, e.g., CQI/PMI/RI. Wireless device transmission ofSRS (sounding reference signal) may be used for CSI estimation at basestation exploiting channel reciprocity. Combinations of full or subsetof above three may also be possible.

For the CoMP schemes that require feedback, individual per-cell feedbackmay be considered as baseline. Complementary inter-cell feedback mightbe needed. Wireless device CoMP feedback reports may target the servingcell (on UL resources from serving cell) as baseline when X2 interfaceis available and is adequate for CoMP operation in terms of latency andcapacity. In this case, the reception of wireless device reports atcells other than the serving cell is a network implementation choice.

According to some of the various aspects of embodiments, explicitfeedback in support of DL CoMP may be characterized by having a channelpart and a noise-and-interference part. For each cell in the wirelessdevice's measurement set that is reported in a given subframe, one orseveral channel properties may be reported. Channel properties mayinclude but are not limited to the following (‘i’ is the cell index):Channel matrix (Hi)—short term (instantaneous), the full matrix Hi, ormain eigen component(s) of Hi. Transmit channel covariance (Ri), whereRi=(sum{Hij†Hij})/J, j=0, 1, 2, . . . , J−1, (‘j’ is span over time orfrequency), the full matrix Ri, or main eigen component(s) of Ri.Inter-cell channel properties may also be reported. Noise- andinterference part may include Interference outside the cells reported bythe wireless device (CoMP transmission points), total receive power (Io)or total received signal covariance matrix, covariance matrix of thenoise-and-interference, the full matrix, or main eigen component(s).

Different forms of implicit feedback in support of DL CoMP may includethe following areas. The feedback may be based on one or a combinationof two or more of the following: Single vs. Multi user MIMO, single cellvs. coordinated transmission, transmit precoder, etc. Within coordinatedtransmission, single point (CB/CS) vs. multi-point (JP) transmission maybe considered. Within joint processing CoMP, subsets of transmissionpoints or subsets of reported cells (Joint Transmission) may beconsidered. CoMP transmission point(s) may be based on a Dynamic CellSelection. Transmit precoder (i.e. tx weights) in JP may includemultiple single-cell or multi-cell PMI capturing coherent ornon-coherent channel across reported cells. Transmit precoder (i.e.transmitter weights) in CB/CS may include single-cell or multiplesingle-cell PMIs capturing channel from the reported cell(s) to thewireless device. Transmit precoder may be based on or derived from thePMI weight. Other types of feedbacks, e.g. main Multi-celleigen-component, instead of PMI may be considered. Receive processing(i.e. receiver weights), or interference based on particulartransmitter/receiver processing may also be considered.

There may be a need for the wireless device to convey to the network thehypothesis or hypotheses used (explicit signaling of hypothesis to basestation). And/or, there may be a semi-static hypothesis configuratione.g. grouping of hypotheses (explicit signaling of hypothesis to thewireless device). And/or, precoded RS may be used to allow wirelessdevice to generate refined CQI/RI feedback.

The PUCCH may be mapped to a control channel resource in the uplink. TheCSI may inform the scheduler about the current channel conditions asseen by the wireless device. If MIMO transmission is used, the CSIincludes necessary MIMO-related feedback. The HARQ feedback in responseto downlink data transmission comprises of a single ACK/NAK bit pertransport block in case of non-bundling configuration. PUCCH resourcesfor SR (scheduling request) and CSI reporting may be assigned andrevoked through RRC signaling. An SR is not necessarily assigned towireless devices acquiring synchronization through the RACH (i.e.synchronized wireless devices may or may not have a dedicated SRchannel). PUCCH resources for SR and CQI are lost when the wirelessdevice is no longer synchronized. PUCCH may be transmitted on PCell incarrier aggregation. The physical layer may support simultaneoustransmission of PUCCH and PUSCH. A wireless device may transmit PUCCH onthe primary cell.

According to some of the various aspects of embodiments, the time andfrequency resources that can be used by the wireless device to reportCSI which may include channel quality indicator (CQI), precoding matrixindicator (PMI), precoding type indicator (PTI), and/or rank indicator(RI) may be controlled by the base station. For spatial multiplexing,the wireless device may determine a RI corresponding to the number ofuseful transmission layers. For transmit diversity RI is equal to one. Awireless device may be configured with or without PMI/RI reporting bythe higher layer parameter. CSI reporting may be periodic or aperiodic.

If the wireless device is configured with more than one serving cell, itmay transmit periodic CSI for all activated serving cells as configuredby higher layers. If a wireless device is not configured forsimultaneous PUSCH and PUCCH transmission, it may transmit periodic CSIreporting on PUCCH in subframes with no PUSCH allocation. If a wirelessdevice is configured for simultaneous PUSCH and PUCCH transmission, itmay transmit periodic CSI reporting on PUCCH in subframes with orwithout PUSCH allocation. If a wireless device is not configured forsimultaneous PUSCH and PUCCH transmission, it may transmit periodic CSIreporting on PUSCH of the serving cell, preferably with smallest ServingCell Index, in subframes with a PUSCH allocation, where the wirelessdevice may use the same PUCCH-based periodic CSI reporting format onPUSCH.

A wireless device may transmit aperiodic CSI reporting on PUSCH. Foraperiodic CQI/PMI reporting, RI reporting may be transmitted if theconfigured CSI feedback type supports RI reporting. In case bothperiodic and aperiodic CSI reporting would occur in the same subframe,the wireless device may transmit the aperiodic CSI report in thatsubframe. When reporting RI the wireless device reports a singleinstance of the number of useful transmission layers.

According to some of the various aspects of embodiments, when reportingPMI the wireless device may report either a single or a multiple PMIreports. Precoding feedback is used for channel dependent codebook basedprecoding and relies on wireless devices reporting precoding matrixindicator (PMI). The wireless device may report PMI if configured withPMI/RI reporting. The number of RBs (resource blocks) represented by asingle wireless device PMI report may be all RBs or a smaller subset ofRBs. The number of RBs represented by a single PMI report issemi-statically configured by higher layer signaling. A wireless devicemay be restricted to report PMI, RI and PTI within a precoder codebooksubset configured by higher layer signaling. For a specific precodercodebook and associated transmission mode, the parameter may specify allpossible precoder codebook subsets from which the wireless device mayassume the base station may be using when the wireless device isconfigured in the relevant transmission mode. The set of sub-bands (S) awireless device may evaluate for CQI reporting spans the entire downlinksystem bandwidth. A sub-band is a set of k contiguous PRBs where k is afunction of system bandwidth. The sub-bands may be indexed in the orderof increasing frequency and non-increasing sizes starting at the lowestfrequency.

A wireless device may perform aperiodic CSI reporting using the PUSCH insubframe n+k on serving cell c, upon decoding in subframe n either: anuplink DCI format, or a Random Access Response Grant, for serving cell cif the respective CSI request field is set to trigger a report and isnot reserved. The minimum reporting interval for aperiodic reporting ofCQI and PMI and RI may be 1 subframe. The sub-band size for CQI may bethe same for transmitter-receiver configurations with and withoutprecoding. A wireless device is semi-statically configured by higherlayers to feed back CQI and PMI and corresponding RI on the same PUSCHusing a CSI reporting mode.

A wireless device is semi-statically configured by higher layers toperiodically feedback different CSI (CQI, PMI, PTI, and/or RI) on thePUCCH. The periodic CSI reporting mode for each serving cell isconfigured by higher-layer signaling. For the wireless device-selectedsub-band CQI, a CQI report in a certain subframe of a certain servingcell describes the channel quality in a particular part or in particularparts of the bandwidth of that serving cell described subsequently asbandwidth part (BP) or parts. The bandwidth parts may be indexed in theorder of increasing frequency and non-increasing sizes starting at thelowest frequency.

If the wireless device is configured with more than one serving cell,the wireless device may transmit a CSI report of one serving cell in anygiven subframe. If the wireless device is not configured forsimultaneous PUSCH and PUCCH transmission or, if the wireless device isconfigured for simultaneous PUSCH and PUCCH transmission and nottransmitting PUSCH, in case of collision between CSI and positive SR ina same subframe, CSI may be dropped. A RI report for a serving cell in aperiodic reporting mode may be valid for CQI/PMI report for that servingcell on that periodic CSI reporting mode.

Based on an unrestricted observation interval in time and frequency, thewireless device may derive for each CQI value reported in uplinksubframe n the highest CQI index between 1 and 15, which satisfies thefollowing condition, or CQI index 0 if CQI index 1 does not satisfy thecondition: A single PDSCH transport block with a combination ofmodulation scheme and transport block size corresponding to the CQIindex, and occupying a group of downlink physical resource blocks termedthe CSI reference resource, may be received with a transport block errorprobability not exceeding 0.1.

Physical Uplink Control Channel Transmission:

According to some of the various aspects of embodiments, if the wirelessdevice is configured for a single serving cell and is not configured forsimultaneous PUSCH and PUCCH transmissions, then in subframe n uplinkcontrol information (UCI) may be transmitted: on PUCCH, if the wirelessdevice is not transmitting on PUSCH, or on PUSCH if the wireless deviceis transmitting on PUSCH in subframe n unless the PUSCH transmissioncorresponds to a Random Access Response Grant or a retransmission of thesame transport block as part of the contention based random accessprocedure, in which case UCI may not be transmitted. If the wirelessdevice is configured for a single serving cell and simultaneous PUSCHand PUCCH transmission, then in subframe n UCI may be transmitted onPUCCH, or on PUCCH and PUSCH depending on the wireless deviceconfiguration.

If the wireless device is configured with more than one serving cell andis not configured for simultaneous PUSCH and PUCCH transmission, then insubframe n UCI may be transmitted on PUCCH if the wireless device is nottransmitting PUSCH; on PUSCH of the serving cell if the UCI includesaperiodic CSI or aperiodic CSI and HARQ-ACK; on primary cell PUSCH ifthe UCI comprises of periodic CSI and/or HARQ-ACK and if the wirelessdevice is transmitting on the primary cell PUSCH in subframe n unlessthe primary cell PUSCH transmission corresponds to a Random AccessResponse Grant or a retransmission of the same transport block as partof the contention based random access procedure, in which case UCI isnot transmitted; or on PUSCH of the secondary cell with smallest SCellIndex if the UCI comprises of periodic CSI and/or HARQ-ACK and if thewireless device is not transmitting PUSCH on primary cell but istransmitting PUSCH on at least one secondary cell.

If the wireless device is configured with more than one serving cell andsimultaneous PUSCH and PUCCH transmission, then in subframe n UCI may betransmitted: on PUCCH if the UCI includes HARQ-ACK and/or SR; on PUCCHif the UCI includes periodic CSI; on PUCCH and primary cell PUSCH if theUCI comprises of HARQ-ACK and periodic CSI and the wireless device istransmitting PUSCH on the primary cell, in which case the HARQ-ACK istransmitted on PUCCH and the periodic CSI is transmitted on PUSCH unlessthe primary cell PUSCH transmission corresponds to a Random AccessResponse Grant or a retransmission of the same transport block as partof the contention based random access procedure, in which case periodicCSI is not transmitted; on PUCCH and PUSCH of the secondary cell withthe smallest SCell Index if the UCI includes HARQ-ACK and periodic CSIand if the wireless device is not transmitting PUSCH on primary cell butis transmitting PUSCH on at least one secondary cell, in which case, theHARQ-ACK is transmitted on PUCCH and the periodic CSI is transmitted onPUSCH; on PUCCH and PUSCH if the UCI includesHARQ-ACK/HARQ-ACK+SR/positive SR and aperiodic CSI in which case theHARQ-ACK/HARQ-ACK+SR/positive SR is transmitted on PUCCH and theaperiodic CSI is transmitted on PUSCH of the serving cell.

The downlink MIMO channel formed by the T antennas at base station andthe R antennas at wireless device may be characterized by an R×T MIMOchannel matrix H_(DL)(k) for each subcarrier k. H_(DL)(k) may beexpressed as:

$\begin{matrix}{{{H_{DL}(k)} = \begin{bmatrix}{h_{1,1}(k)} & {h_{1,2}(k)} & \ldots & {h_{1,T}(k)} \\{h_{2,1}(k)} & {h_{2,2}(k)} & \ldots & {h_{2,T}(k)} \\\vdots & \vdots & \ddots & \vdots \\{h_{R,1}(k)} & {h_{R,2}(k)} & \ldots & {h_{R,T}(k)}\end{bmatrix}},} & {{Eq}.\mspace{14mu}(1)}\end{matrix}$

where entry h_(i,j)(k), for i=1, . . . , R and j=1, . . . , T, is acomplex gain between base station antenna j and wireless device antennai for subcarrier k. The uplink MIMO channel formed by the R antennas atwireless device and the T antennas at base station may be characterizedby a T×R MIMO channel matrix H_(UL)(k) for each subcarrier k. H_(UL)(k)may have the form shown in equation (1).

For FDD, the downlink MIMO channel matrix H_(DL)(k) may not becorrelated with the uplink MIMO channel matrix H_(UL)(k). The basestation may estimate H_(UL)(k) based on the sounding reference signaltransmitted by the wireless device. The base station may send precodingmatrix indicator (PMI) information obtained from H_(UL)(k) to thewireless device for precoding on the uplink. Similarly, the wirelessdevice may estimate H_(DL)(k) based on the cell-specific referencesignal transmitted by the base station. The wireless device may send PMIinformation obtained from H_(DL)(k) to the base station for precoding onthe downlink.

For TDD, the downlink MIMO channel matrix H_(DL)(k) may be correlatedwith the uplink MIMO channel matrix H_(UL)(k) and may be assumed to bereciprocal of one another, so that H_(UL)(k)=H_(DL) ^(T)(k), where“^(T)” denotes a transpose. In this case, the base station may estimateH_(UL)(k) based on the sounding reference signal transmitted by thewireless device. The base station may estimate H_(DL)(k) based on theestimated H_(UL)(k) by assuming channel reciprocity. The base stationmay then use H_(DL)(k) to obtain PMI information for the downlink.Similarly, the wireless device may estimate H_(DL)(k) based on thecell-specific reference signal transmitted by the base station. Thewireless device may estimate H_(UL)(k) based on the estimated H_(DL)(k)by assuming channel reciprocity. The wireless device may then useH_(UL)(k) to obtain PMI information for the uplink.

An overall downlink MIMO channel is composed of the transmit chains forthe T antennas at the base station, the downlink MIMO channel, and thereceive chains for the R antennas at the wireless device. An overalluplink MIMO channel is composed of the transmit chains for the Rantennas at the wireless device, the uplink MIMO channel, and thereceive chains for the T antennas at the base station. For FDD, theoverall downlink MIMO channel for each link may be estimated based on areference signal received via that link. For TDD, the overall downlinkMIMO channel may not be reciprocal of the overall uplink MIMO channel,even if H_(UL)(k)=H_(DL) ^(T)(k), due to differences between theresponses of the transmit and receive chains at the base station and thewireless device. Calibration may be performed to determine a calibrationmatrix that may be applied (e.g., at the base station) to account forthe differences between the responses of the transmit and receive chainsat the base station and the wireless device. With the calibration matrixapplied, the overall downlink MIMO channel may be assumed to bereciprocal of the overall uplink MIMO channel. For simplicity, thefollowing description assumes that the transmit and receive chains haveflat responses, the calculation matrix is an identity matrix I, theoverall downlink MIMO channel matrix is H_(DL)(k), the overall uplinkMIMO channel matrix is H_(UL)(k), and H_(UL)(k)=H_(DL) ^(T)(k) for TDD.

For both FDD and TDD, the base station may transmit M symbol streams onM layers to the wireless device, where in general 1≦M≦min {T, R}. Thelayers may be viewed as spatial channels of a MIMO channel. Similarly,the wireless device may transmit M symbol streams on M layers to thebase station. The number of symbol streams to send on the uplink may ormay not be equal to the number of symbol streams to send on thedownlink. For clarity, data transmission on the downlink is describedbelow.

According to some of the various aspects of embodiments, goodperformance may be achieved by transmitting data on eigenmodes of a MIMOchannel. The eigenmodes may be viewed as orthogonal spatial channels. Totransmit data on eigenmodes, the base station may obtain a precodingmatrix based on ideal eigen-beamforming or pseudo eigen-beamforming andmay then perform precoding with the precoding matrix. The followingtable summarizes the characteristics of ideal and pseudoeigen-beamforming.

Beamforming Type Description Ideal eigen- Precoding matrix is derivedbased beamforming on a MIMO channel matrix. Pseudo eigen- Precodingmatrix is derived based beamforming on a pseudo-beam matrix.

For ideal eigen-beamforming, the downlink MIMO channel matrix H_(DL)(k)may be diagonalized with singular value decomposition, as follows:H _(DL)(k)=U(k)Σ(k)V ^(H)(k),  Eq (2)

where U(k) is an R×R unitary matrix of left eigenvectors of H_(DL)(k),V(k) is a T×T unitary matrix of right eigenvectors of H_(DL)(k), Σ(k) isan R×T diagonal matrix of singular values of H_(DL)(k), and “^(H)”denotes a Hermitian or conjugate transpose.

A unitary matrix has columns that are orthogonal to one another, andeach column has unit power. A diagonal matrix has possible non-zerovalues along the diagonal and zeros elsewhere. The singular values inΣ(k) are indicative of the channel gains of the eigenmodes of H_(DL)(k)obtained via singular value decomposition. Matrix V(k) may also bereferred to as an eigen-beam matrix, a beamforming matrix, etc. Theeigen-beam matrix V(k) may also be obtained by performing eigenvaluedecomposition of a covariance matrix of H_(DL)(k). The eigenvaluedecomposition may be expressed as

H_(DL) ^(H)(k) H_(DL)(k)=V(k)Λ(k)V^(H)(k), where Λ(k)=Σ^(H)(k)Σ(k) andΛ(k) is a diagonal matrix of eigenvalues of H_(DL)(k).

The base station may transmit data on M eigenmodes to the wirelessdevice, where 1≦M≦min {T, R}. The number of eigenmodes (M) to use fordata transmission may also be referred to as the rank of the datatransmission. A precoding matrix W_(IBF)(k) may be formed based on Mcolumns of V(k) for the M eigenmodes. In one design, W_(IBF)(k) may beformed as follows:W _(IBF)(k)=[v ₁(k), . . . , v _(M)(k)],  Eq (3)

where v_(m)(k) is the column of V(k) for the m-th selected eigenmode,for m=1, . . . , M, and

W_(IBF)(k) is a T×M precoding matrix for ideal eigen-beamforming (IBF).

In another design, a codebook of precoding matrices may be supported.W_(IBF)(k) may be formed based on a preceding matrix in the codebookthat most closely matches V(k), e.g., have the closest distance to V(k).

The base station may perform symbol scaling and preceding for idealeigen-beamforming as follows:x _(IBF)(k)=W _(IBF)(k)G(k)d(k),  Eq (4)

where d(k) is an M×1 vector of data symbols to send on subcarrier k,G(k) is an M×M diagonal matrix of gains for the data symbols, and x(k)is a T×1 vector of output symbols for subcarrier k.

The wireless device may obtain received symbols from the R antennas,which may be expressed as:

$\begin{matrix}\begin{matrix}{{r(k)} = {{{H_{DL}(k)}{x_{IBF}(k)}} + {n(k)}}} \\{= {{{H_{DL}(k)}{W_{IBF}(k)}{G(k)}{d(k)}} + {n(k)}}} \\{= {{{H_{EDL}(k)}d(k)} + {n(k)}}}\end{matrix} & {{Eq}\mspace{14mu}(5)}\end{matrix}$

where H_(EDL)(k)=H_(DL)(k)W_(IBF)(k)G(k) is an R×M effective MIMOchannel matrix for ideal eigen-beamforming,

r(k) is an R×1 vector of received symbols for subcarrier k, and

n(k) is an R×1 vector of noise and interference for subcarrier k.

The noise and interference may have a covariance matrix ofR_(nn)(k)=E{n(k)n^(H)(k)}, where E{ } denotes an expectation. The noiseand interference may be assumed to be additive white Gaussian noise(AWGN) with a zero mean vector and a covariance matrix ofR_(nn)(k)=σ_(n) ²I, where σ_(n) ² is the variance of the noise andinterference.

The wireless device may perform MIMO detection based on minimum meansquare error (MMSE), zero-forcing equalization, MMSE with successiveinterference cancellation, or some other MIMO detection technique. ForMMSE, the wireless device may derive an M×R detection matrix M(k) foreach subcarrier k, as follows:M(k)=D(k)[H _(EHL) ^(H)(k)H _(EDL)(k)+R _(nn)(k)]⁻¹ H _(EDL)^(H)(k),  Eq (6)

where Z(k)=[H_(EHL) ^(H)(k)H_(EDL)(k)+R_(nn)(k)]⁻¹H_(EDL)^(H)(k)H_(EDL)(k), and D(k)=[diag Z(k)]⁻¹ is a diagonal matrix ofscaling values to obtain normalized symbol estimates.

The wireless device may perform MIMO detection as follows:{circumflex over (d)}(k)=M(k)r(k),  Eq (7)

where {circumflex over (d)}(k) is an M×1 vector of symbol estimates forsubcarrier k. {circumflex over (d)}(k) is an estimate of d(k) sent bythe base station.

A signal-to-and-noise-and-interference ratio (SINR) for each eigenmodemay be expressed as:

$\begin{matrix}{{{{SINR}_{m}(k)} = \frac{z_{m}(k)}{1 - {z_{m}(k)}}},{m = 1},\ldots\mspace{14mu},M} & {{Eq}\mspace{14mu}(8)}\end{matrix}$

where z_(m)(k) is the m-th diagonal element of Z(k), and SINR_(m)(k) isthe SINR of eigenmode m for subcarrier k.

In general, the SINR may be dependent on the MIMO detection techniqueused by the wireless device. Different MIMO detection techniques may beassociated with different equations for computing SINR.

Rank prediction may be performed (e.g., by the wireless device) todetermine M eigenmodes to use for data transmission. In one design ofrank prediction, an overall throughput may be computed for each possiblecombination of eigenmodes that can be used for data transmission. For agiven eigenmode combination or hypothesis, the available transmit powerof P_(avail) may be allocated to the M eigenmodes in that combinationbased on uniform power allocation, so that P_(m)=P_(avail)/M and P_(m)is the transmit power allocated to eigenmode m. The power allocation mayalso be based on water-filling or some other technique. The gain matrixG(k) may be computed based on the transmit power allocated to the Meigenmodes. The gain matrix G(k) may include a non-zero gain for eachselected eigenmode and a zero gain for each unselected eigenmode. Theeffective MIMO channel matrix H_(EDL)(k) may then be determined based onthe MIMO channel matrix H_(DL)(k), the precoding matrix W_(IBF)(k), andthe gain matrix G(k). The SINRs of the M eigenmodes may be determinedbased on the effective MIMO channel matrix H_(EDL)(k) and the noisecovariance matrix R_(nn)(k), as described above. The overall throughputfor the current hypothesis may then be determined based on the SINRs ofthe M eigenmodes. The computation described above may be repeated foreach possible combination of eigenmodes to obtain an overall throughputfor that combination. The combination of eigenmodes with the highestoverall throughput may be selected for data transmission.

For downlink transmission, the wireless device may convert the SINR ofeach of the M eigenmodes to a CQI value based on a predeterminedmapping. The wireless device may obtain CQI information for the Meigenmodes, which may comprise (i) a CQI value for each eigenmode or(ii) a base CQI for the first eigenmode and a delta CQI for thedifference between the CQI values of successive eigenmodes. The wirelessdevice may send the CQI information to the base station. The basestation may select a modulation and coding scheme (MCS) for eacheigenmode based on the CQI value for that eigenmode.

For pseudo eigen-beamforming, a pseudo-beam matrix may be formed foreach subcarrier k, as follows:B(k)=[h _(DL,1)(k), . . . , h _(DL,R)(k),b _(R+1)(k), . . . , b_(T)(k)],  Eq (9)

where h_(DL,i)(k) is a T×1 channel vector for wireless device antenna i,

b_(i)(k) is a T×1 random vector, and

B(k) is a T×T pseudo-beam matrix.

In general, B(k) may be formed with zero or more channel vectors inH_(DL)(k) for zero or more wireless device antennas. Each channel vectorh_(DL,i)(k) may correspond to one row of H_(DL)(k). The remainingcolumns of B(k) may be random vectors, which may be columns of adiscrete Fourier transform (DFT) matrix, a Hadamard or Walsh matrix, orsome other matrix.

Example embodiments of the invention may enable channel stateinformation transmission in wireless communication systems. Otherexample embodiments may comprise a non-transitory tangible computerreadable media comprising instructions executable by one or moreprocessors to cause to transmit channel state information. Yet otherexample embodiments may comprise an article of manufacture thatcomprises a non-transitory tangible computer readable machine-accessiblemedium having instructions encoded thereon for enabling programmablehardware to cause a device (e.g. wireless communicator, UE, basestation, etc.) to transmit channel state information. The device mayinclude processors, memory, interfaces, and/or the like. Other exampleembodiments may comprise communication networks comprising devices suchas base stations, wireless devices (or user equipment: UE), servers,switches, antennas, and/or the like.

FIG. 6 depicts an example flow chart for channel state informationtransmission in a wireless device as per an aspect of an embodiment ofthe present invention. According to some of the various aspects ofembodiments, a wireless device may receive at least one control messagefrom a first base station in the plurality of base stations. The atleast one control message may configure measurement parameters of thewireless device. The measurement configuration may trigger measurementsof channel state information corresponding to a subset of carriers inthe plurality of base stations. The at least one control message mayconfigure at least one of the following: a) a channel state informationtransmission period, b) a channel state information transmissionresource, c) a channel state information measurement resource, d) aphysical uplink control channel format, and/or e) a list of carriers forthe measurement of channel state information. Carriers in the list ofcarriers may belong to at least two base stations in the plurality ofbase stations or may belong to at least two sectors of the first basestation.

The wireless device may measure the channel state information for eachactive carrier in the list of carriers on a plurality of OFDMsubcarriers and a first plurality of subframes in the plurality ofsubframes determined by the measurement resource based on theconfiguration received in the at least one control message. The wirelessdevice may multiplex and encode the channel state measurementinformation based on the physical uplink control channel format. Thewireless device may spread by multiplying the multiplexed and encodedinformation by a sequence generated in the wireless device. The wirelessdevice may transmit the spread information using single-carrier OFDMtransmission on the channel state information transmission resourceaccording to the channel state information transmission period. Thewireless device may simultaneously receive signals from a subset ofcarriers in the list of carriers. The signals carry a plurality of datapackets for the wireless device. Carriers in the subset of carriers maybelong to the at least two base stations or may belong to at least twosectors of the first base station.

According to some of the various aspects of embodiments, the at leasttwo base stations may comprise the first base station. The at least onecontrol message may comprise at least one of the following: an RRCConnection Reconfiguration, an RRC connection establishment, and a PDCCHmessage. For example, the wireless device may transmit the channel statemeasurement information of only one carrier in a subframe. The wirelessdevice may transmit the channel state measurement information of onlyone carrier in a subframe, and may alternate transmission of the channelstate measurement information of each carrier in the list of carriers ina pre-defined order. The encoded channel state measurement informationmay comprise information about transmission channel of a plurality ofcarriers.

The channel state information transmission period may be in terms ofnumber of subframes. The channel state information may comprise at leastone of the following: a channel quality indicator (CQI), a precodingmatrix indicator (PMI), a precoding type indicator (PTI), and a rankindicator (RI).

The rank indicator may correspond to the number of transmission layersfor downlink transmission. The precoding matrix indicator (PMI) may bemeasured for the entire bandwidth or a group of resource blocksaccording to the wireless device configuration. The channel qualityindicator (CQI) may be measured for the entire bandwidth or a group ofresource blocks according to the wireless device configuration. Thewireless device may be in connected state and no data packet may betransmitted in physical uplink shared channel simultaneously in asubframe in which the spread information is transmitted. The pluralityof OFDM subcarriers of a carrier may comprise reference signal symbolstransmitted on the carrier. The first plurality of subframes may notcomprise almost blank subframes. The first plurality of subframes maynot comprise broadcast and multicast subframes. The measurement resourcemay determine sub-band or wideband channel state measurement, whereinthe wideband corresponds to a carrier bandwidth. The measurementresource may comprise reference signal in the sub-band or the wideband.The measurement resource may determine a plurality of resource blocksthat are object of the channel state information measurement. Themeasurement resource may determine a plurality of subframes that areobject of the channel state information measurement.

The channel state information may be quantized separately for differentcarriers in the subset of carriers. The channel state information may bequantized jointly across the subset of carriers. The channel stateinformation may be represented by a product of a first channel stateinformation matrix and a second channel state information matrix. Thefirst channel state information matrix may be global channel stateinformation and may comprise joint information about all active carriersin the subset of carriers. The second channel state information matrixmay be local channel state information and may comprise separateinformation about different active carriers in the subset of carriers.The first channel state information matrix may comprise informationabout channel eigen values. The second channel state information matrixmay comprise information about channel eigen vectors. The first channelstate information matrix may be left multiplied by the second channelstate information matrix. The first channel state information matrix maybe right multiplied by the second channel state information matrix.

The channel state information may be quantized using a multipledescription code. The channel state information may be transmitted overa plurality of separate instances of the physical uplink controlchannel. Each instance in the plurality of separate instances of thephysical uplink control channel may carry coarse channel stateinformation. The channel state information may be encoded separately fordifferent carriers. The channel state information may be encoded jointlyacross the subset of carriers. The channel state information forcarriers other than a primary carrier of the wireless device may beencoded differentially with respect to the channel state information forthe primary carrier of the wireless device. The differentially encodedchannel state information may comprise phase and amplitude information.The differentially encoded channel state information may comprise phaseinformation, and may not comprise amplitude information. Thedifferentially encoded channel state information may comprise amplitudeinformation, and may not comprise phase information. The channel stateinformation may be transmitted using hierarchical modulation. Thechannel state information may be transmitted using multilevel coding.

The physical uplink control channel format may determine whether any ofthe following measurements are comprised in the channel stateinformation: a channel quality indicator (CQI), a precoding matrixindicator (PMI), a precoding type indicator (PTI), or a rank indicator(RI). The sequence may be determined based on a temporary identifierassigned to the wireless device by a base station. The channel stateinformation measurement resource may comprise at least an uplink carrierresource block. The physical uplink control channel may be transmittedon an uplink carrier corresponding to a downlink primary carrier. Thechannel state information may be transmitted on the physical uplinkcontrol channel, if there is no transmission on physical uplink sharedchannel in the same subframe, and the wireless device is not configuredto transmit simultaneously on the physical uplink control channel andthe physical uplink shared channel. The channel state information may betransmitted on the physical uplink control channel with or withoutphysical uplink shared channel allocation, if the wireless device isconfigured to transmit simultaneously on the physical uplink controlchannel and an uplink data channel.

According to some of the various aspects of embodiments, each basestation in a plurality of base stations of a network comprises at leastone carrier. The wireless device may receive at least one controlmessage from a first base station in the plurality of base stations. Theat least one control message may configure measurement parameters of thewireless device. The measurement configuration may trigger measurementsof channel state information corresponding to a subset of carriers inthe plurality of base stations. The at least one control message mayconfigure at least one of the following: a channel state informationtransmission period, a channel state information transmission resource,a physical uplink control channel format, and/or a list of carriers forthe measurement of channel state information. Carriers in the list ofcarriers may belong to at least two base stations in the plurality ofbase stations or may belong to at least two sectors of the first basestation in the plurality of base stations. In an example embodiment, thewireless device may measure channel state information only for activeconfigured carriers.

The wireless device may measure the channel state information for eachactive carrier in the list of carriers based on the configurationreceived in the at least one control message. The wireless device maymultiplex and encode the channel state measurement information based onthe physical uplink control channel format. The wireless device mayspread by multiplying the multiplexed and encoded information by asequence generated in the wireless device. The wireless device maytransmit the spread information using single-carrier OFDM transmissionon the channel state information transmission resource according to thechannel state information transmission period. The wireless device maysimultaneously receive signals from a subset of active carriers in thelist of carriers. The signals may carry a plurality of data packets forthe wireless device. Carriers in the subset of carriers may belong tothe at least two base stations or may belong to at least two sectors ofthe first base station.

FIG. 7 depicts an example flow chart for channel state informationtransmission in a wireless device as per an aspect of an embodiment ofthe present invention. According to some of the various aspects ofembodiments, a network comprises a plurality of base stations. Each basestation may comprise at least one carrier. The wireless device mayreceive at least one control message from a first base station in theplurality of base stations. The at least one control message mayconfigure measurement parameters of the wireless device. The measurementconfiguration may trigger measurements of channel state informationcorresponding to a subset of carriers in the plurality of base stations.The at least one control message may configure at least one of thefollowing: an uplink transmission resource, physical uplink channelformat, and/or a list of carriers for the measurement of channel stateinformation. Carriers in the list of carriers may belong to at least twobase stations in the plurality of base stations or may belong to atleast two sectors of the first base station in the plurality of basestations.

The wireless device may measure the channel state information for eachactive carrier in the list of carriers based on the configurationreceived in the at least one control message. The wireless device maymultiplex and encode the channel state measurement information based onthe physical uplink channel format. The wireless device may transmit theinformation using single-carrier OFDM transmission on the uplinktransmission resource. The wireless device may simultaneously receivesignals from a subset of active carriers in the list of carriers. Thesignals may carry a plurality of data packets for the wireless device.Carriers in the subset of carriers may belong to the at least two basestations or may belong to at least two sectors of the first basestation.

The at least one control message may comprise RRC messages and PDCCHmessages. The physical uplink channel format may determine the format ofphysical uplink control channel or physical uplink shared channel orboth. If the wireless device is not configured for simultaneoustransmission on the physical uplink control channel and a physicaluplink shared channel, the wireless device may transmit the channelstate information on the physical uplink shared channel of a servingcell with smallest Serving Cell Index, in subframes with a physicaluplink shared channel allocation. The channel state information may bequantized using a multiple description code. The channel stateinformation may be transmitted over a plurality of separate instances ofthe physical uplink channel.

According to some of the various aspects of embodiments, a first basestation may transmit at least one control message to a wireless device.The at least one control message may configure measurement parameters ofthe wireless device. The measurement configuration may triggermeasurements of channel state information corresponding to a subset ofactive carriers in the plurality of base stations. The at least onecontrol message may configure at least one of the following: a) achannel state information transmission period, b) a channel stateinformation transmission resource, c) a channel state informationmeasurement resource, d) a physical uplink control channel format, ande) a list of carriers for the measurement of channel state informationby the wireless device. Carriers in the list of carriers may belong toat least two base stations in the plurality of base stations or maybelong to at least two sectors of the first base station in theplurality of base stations.

The first base station may receive spread information from the wirelessdevice using single-carrier OFDM reception on the channel stateinformation transmission resource according to the channel stateinformation transmission period. The wireless device may measure thechannel state information for each carrier in the list of carriers on aplurality of OFDM subcarriers and a first plurality of subframes in theplurality of subframes determined by the measurement resource based onthe configuration received in the at least one control message. Thewireless device may multiplex and encode the channel state measurementinformation based on the physical uplink control channel format. Thewireless device may spread by multiplying the multiplexed and encodedinformation by a sequence generated in the wireless device to generatethe spread information. Signals may be simultaneously transmitted from asubset of active carriers in the list of carriers. The signals may carrya plurality of data packets for the wireless device. Active carriers inthe subset of carriers may belong to the at least two base stations ormay belong to at least two sectors of the first base station.

The at least two base stations may comprise the first base station. Theat least one control message comprises at least one of the following: a)an RRC Connection Reconfiguration, b) an RRC connection establishment,and c) a PDCCH message. The first base station may receive the channelstate measurement information of only one carrier in a subframe. Thefirst base station may receive the channel state measurement informationof only one carrier in a subframe. The first base station may alternatereception of the channel state measurement information of each carrierin the list of carriers in a pre-defined order. The encoded channelstate measurement information may comprise information abouttransmission channel of a plurality of carriers. The channel stateinformation transmission period may be in terms of number of subframes.The channel state information may comprise at least one of thefollowing: a) a channel quality indicator (CQI), b) a precoding matrixindicator (PMI), c) a precoding type indicator (PTI), and d) a rankindicator (RI). The rank indicator may correspond to the number oftransmission layers for downlink transmission. The precoding matrixindicator (PMI) may be measured by the wireless device for the entirebandwidth or a group of resource blocks according to the wireless deviceconfiguration. The channel quality indicator (CQI) is measured by thewireless device for the entire bandwidth or a group of resource blocksaccording to the wireless device configuration.

The wireless device may be in connected state and no data packet may bereceived in physical uplink shared channel simultaneously in a subframein which the spread information is received. The plurality of OFDMsubcarriers of a carrier may comprise reference signal symbolstransmitted on the carrier. The first plurality of subframes may notcomprise almost blank subframes. The first plurality of subframes maynot comprise broadcast and multicast subframes. The measurement resourcemay determine sub-band or wideband channel state measurement. Thewideband corresponds to a carrier bandwidth. The measurement resourcemay comprise reference signal in the sub-band or the wideband. Themeasurement resource may determine a plurality of resource blocks thatare object of the channel state information measurement. The measurementresource may determine a plurality of subframes that are object of thechannel state information measurement.

According to some of the various aspects of embodiments, the channelstate information may be quantized separately for different carriers inthe subset of carriers. The channel state information may be quantizedjointly across the subset of carriers. The channel state information maybe represented by a product of a first channel state information matrixand a second channel state information matrix. The first channel stateinformation matrix may be global channel state information and maycomprise joint information about all carriers in the subset of carriers.The second channel state information matrix may be local channel stateinformation and may comprise separate information about differentcarriers in the subset of carriers. The first channel state informationmatrix may comprise information about channel eigen values. The secondchannel state information matrix may comprise information about channeleigen vectors. The first channel state information matrix may be leftmultiplied by the second channel state information matrix. The firstchannel state information matrix may be right multiplied by the secondchannel state information matrix. The channel state information may bequantized using a multiple description code. The channel stateinformation may be received over a plurality of separate instances ofthe physical uplink control channel. Instances in the plurality ofseparate instances of the physical uplink control channel may carrycoarse channel state information.

According to some of the various aspects of embodiments, the channelstate information may be encoded separately for different carriers. Thechannel state information may be encoded jointly across the subset ofcarriers. The channel state information for carriers other than aprimary carrier of the wireless device may be encoded differentiallywith respect to the channel state information for the primary carrier ofthe wireless device. The differentially encoded channel stateinformation may comprise phase and amplitude information. Thedifferentially encoded channel state information may comprise phaseinformation, and may not comprise amplitude information. Thedifferentially encoded channel state information may comprise amplitudeinformation, and may not comprise phase information. The channel stateinformation may be received using hierarchical demodulation. The channelstate information may be received using multilevel decoding. Thephysical uplink control channel format may determine whether any of thefollowing measurements are comprised in the channel state information:a) a channel quality indicator (CQI), b) a precoding matrix indicator(PMI), c) a precoding type indicator (PTI), and d) a rank indicator(RI). The sequence may be determined based on a temporary identifierassigned to the wireless device by a base station. The channel stateinformation measurement resource may comprise at least an uplink carrierresource block. The physical uplink control channel may be received onan uplink carrier corresponding to a downlink primary carrier. Thechannel state information may be received on the physical uplink controlchannel, if there is no reception on physical uplink shared channel inthe same subframe from the wireless device, and the first base stationis not configured to receive simultaneously on the physical uplinkcontrol channel and the physical uplink shared channel from the wirelessdevice. The channel state information may be received on the physicaluplink control channel with or without physical uplink shared channelallocation, if the first base station is configured to receivesimultaneously on the physical uplink control channel and an uplink datachannel from the wireless device.

According to some of the various aspects of embodiments, a first basestation may transmit at least one control message to a wireless device.The at least one control message may configure measurement parameters ofthe wireless device. The measurement configuration may triggermeasurements of channel state information corresponding to a subset ofactive carriers in the plurality of base stations. The at least onecontrol message may configure at least one of the following: a) achannel state information transmission period, b) a channel stateinformation transmission resource, c) a physical uplink control channelformat, and, d) a list of carriers for the measurement of channel stateinformation by the wireless device. Carriers in the list of carriers maybelong to at least two base stations in the plurality of base stationsor may belong to at least two sectors of the first base station in theplurality of base stations. The first base station may receive thespread information from the wireless device using single-carrier OFDMtransmission on the channel state information transmission resourceaccording to the channel state information transmission period.

The wireless device may measure the channel state information for eachactive carrier in the list of carriers based on the configurationreceived in the at least one control message. The wireless device maymultiplex and encode the channel state measurement information based onthe physical uplink control channel format. The wireless device mayspread by multiplying the multiplexed and encoded information by asequence generated in the wireless device to generate the spreadinformation. Signals may be simultaneously transmitted from a subset ofcarriers in the list of carriers. The signals may carry a plurality ofdata packets for the wireless device. Carriers in the subset of carriersmay belong to the at least two base stations or may belong to at leasttwo sectors of the first base station.

According to some of the various aspects of embodiments, a network maycomprise a plurality of base stations. Each base station may comprise atleast one carrier. The first base station may transmit at least onecontrol message to a wireless device. The at least one control messagemay configure measurement parameters of the wireless device. Themeasurement configuration may trigger measurements of channel stateinformation corresponding to a subset of carriers in the plurality ofbase stations. The at least one control message may configure at leastone of the following: a) an uplink transmission resource, b) physicaluplink channel format, and c) a list of carriers for the measurement ofchannel state information by the wireless device. Carriers in the listof carriers may belong to at least two base stations in the plurality ofbase stations or may belong to at least two sectors of the first basestation in the plurality of base stations. The first base station mayreceive the information from the wireless device using single-carrierOFDM transmission on the uplink transmission resource. The wirelessdevice may measure the channel state information for each active carrierin the list of carriers based on the configuration received in the atleast one control message. The wireless device may multiplex and encodethe channel state measurement information based on the physical uplinkchannel format. Signals may be simultaneously transmitted from a subsetof carriers in the list of carriers. The signals may carry a pluralityof data packets for the wireless device. Carriers in the subset ofcarriers may belong to the at least two base stations or may belong toat least two sectors of the first base station.

According to some of the various aspects of embodiments, the at leastone control message may comprise RRC messages and PDCCH messages. Thephysical uplink channel format may determine the format of physicaluplink control channel or physical uplink shared channel or both. If thebase station is not configured for simultaneous reception on a physicaluplink control channel and a physical uplink shared channel from thewireless device, the base station may receive the channel stateinformation on the physical uplink shared channel of a serving cell withsmallest Serving Cell Index, in subframes with a physical uplink sharedchannel allocation. The channel state information may be quantized usinga multiple description code. The channel state information may betransmitted over a plurality of separate instances of the physicaluplink channel.

According to some of the various aspects of embodiments, the packets inthe downlink may be transmitted via downlink physical channels. Thecarrying packets in the uplink may be transmitted via uplink physicalchannels. The baseband data representing a downlink physical channel maybe defined in terms of at least one of the following actions: scramblingof coded bits in codewords to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on layer(s) for transmission on the antenna port(s); mapping ofcomplex-valued modulation symbols for antenna port(s) to resourceelements; and/or generation of complex-valued time-domain OFDM signal(s)for antenna port(s).

Codeword, transmitted on the physical channel in one subframe, may bescrambled prior to modulation, resulting in a block of scrambled bits.The scrambling sequence generator may be initialized at the start ofsubframe(s). Codeword(s) may be modulated using QPSK, 16QAM, 64QAM,128QAM, and/or the like resulting in a block of complex-valuedmodulation symbols. The complex-valued modulation symbols for codewordsto be transmitted may be mapped onto one or several layers. Fortransmission on a single antenna port, a single layer may be used. Forspatial multiplexing, the number of layers may be less than or equal tothe number of antenna port(s) used for transmission of the physicalchannel. The case of a single codeword mapped to multiple layers may beapplicable when the number of cell-specific reference signals is four orwhen the number of UE-specific reference signals is two or larger. Fortransmit diversity, there may be one codeword and the number of layersmay be equal to the number of antenna port(s) used for transmission ofthe physical channel.

The precoder may receive a block of vectors from the layer mapping andgenerate a block of vectors to be mapped onto resources on the antennaport(s). Precoding for spatial multiplexing using antenna port(s) withcell-specific reference signals may be used in combination with layermapping for spatial multiplexing. Spatial multiplexing may support twoor four antenna ports and the set of antenna ports used may be {0,1} or{0, 1, 2, 3}. Precoding for transmit diversity may be used incombination with layer mapping for transmit diversity. The precodingoperation for transmit diversity may be defined for two and four antennaports. Precoding for spatial multiplexing using antenna ports withUE-specific reference signals may also, for example, be used incombination with layer mapping for spatial multiplexing. Spatialmultiplexing using antenna ports with UE-specific reference signals maysupport up to eight antenna ports. Reference signals may be pre-definedsignals that may be used by the receiver for decoding the receivedphysical signal, estimating the channel state, and/or other purposes.

For antenna port(s) used for transmission of the physical channel, theblock of complex-valued symbols may be mapped in sequence to resourceelements. In resource blocks in which UE-specific reference signals arenot transmitted the PDSCH may be transmitted on the same set of antennaports as the physical broadcast channel in the downlink (PBCH). Inresource blocks in which UE-specific reference signals are transmitted,the PDSCH may be transmitted, for example, on antenna port(s) {5, {7},{8}, or {7, 8, . . . , v+6}, where v is the number of layers used fortransmission of the PDSCH.

Common reference signal(s) may be transmitted in physical antennaport(s). Common reference signal(s) may be cell-specific referencesignal(s) (RS) used for demodulation and/or measurement purposes.Channel estimation accuracy using common reference signal(s) may bereasonable for demodulation (high RS density). Common referencesignal(s) may be defined for LTE technologies, LTE-advancedtechnologies, and/or the like. Demodulation reference signal(s) may betransmitted in virtual antenna port(s) (i.e., layer or stream). Channelestimation accuracy using demodulation reference signal(s) may bereasonable within allocated time/frequency resources. Demodulationreference signal(s) may be defined for LTE-advanced technology and maynot be applicable to LTE technology. Measurement reference signal(s),may also called CSI (channel state information) reference signal(s), maybe transmitted in physical antenna port(s) or virtualized antennaport(s). Measurement reference signal(s) may be Cell-specific RS usedfor measurement purposes. Channel estimation accuracy may be relativelylower than demodulation RS. CSI reference signal(s) may be defined forLTE-advanced technology and may not be applicable to LTE technology.

In at least one of the various embodiments, uplink physical channel(s)may correspond to a set of resource elements carrying informationoriginating from higher layers. The following example uplink physicalchannel(s) may be defined for uplink: a) Physical Uplink Shared Channel(PUSCH), b) Physical Uplink Control Channel (PUCCH), c) Physical RandomAccess Channel (PRACH), and/or the like. Uplink physical signal(s) maybe used by the physical layer and may not carry information originatingfrom higher layers. For example, reference signal(s) may be consideredas uplink physical signal(s). Transmitted signal(s) in slot(s) may bedescribed by one or several resource grids including, for example,subcarriers and SC-FDMA or OFDMA symbols. Antenna port(s) may be definedsuch that the channel over which symbol(s) on antenna port(s) may beconveyed and/or inferred from the channel over which other symbol(s) onthe same antenna port(s) is/are conveyed. There may be one resource gridper antenna port. The antenna port(s) used for transmission of physicalchannel(s) or signal(s) may depend on the number of antenna port(s)configured for the physical channel(s) or signal(s).

Element(s) in a resource grid may be called a resource element. Aphysical resource block may be defined as N consecutive SC-FDMA symbolsin the time domain and/or M consecutive subcarriers in the frequencydomain, wherein M and N may be pre-defined integer values. Physicalresource block(s) in uplink(s) may comprise of M×N resource elements.For example, a physical resource block may correspond to one slot in thetime domain and 180 kHz in the frequency domain. Baseband signal(s)representing the physical uplink shared channel may be defined in termsof: a) scrambling, b) modulation of scrambled bits to generatecomplex-valued symbols, c) mapping of complex-valued modulation symbolsonto one or several transmission layers, d) transform precoding togenerate complex-valued symbols, e) precoding of complex-valued symbols,f) mapping of precoded complex-valued symbols to resource elements, g)generation of complex-valued time-domain SC-FDMA signal(s) for antennaport(s), and/or the like.

For codeword(s), block(s) of bits may be scrambled with UE-specificscrambling sequence(s) prior to modulation, resulting in block(s) ofscrambled bits. Complex-valued modulation symbols for codeword(s) to betransmitted may be mapped onto one, two, or more layers. For spatialmultiplexing, layer mapping(s) may be performed according to pre-definedformula (s). The number of layers may be less than or equal to thenumber of antenna port(s) used for transmission of physical uplinkshared channel(s). The example of a single codeword mapped to multiplelayers may be applicable when the number of antenna port(s) used forPUSCH is, for example, four. For layer(s), the block of complex-valuedsymbols may be divided into multiple sets, each corresponding to oneSC-FDMA symbol. Transform precoding may be applied. For antenna port(s)used for transmission of the PUSCH in a subframe, block(s) ofcomplex-valued symbols may be multiplied with an amplitude scalingfactor in order to conform to a required transmit power, and mapped insequence to physical resource block(s) on antenna port(s) and assignedfor transmission of PUSCH.

According to some of the various embodiments, data may arrive to thecoding unit in the form of two transport blocks every transmission timeinterval (TTI) per UL cell. The following coding actions may beidentified for transport block(s) of an uplink carrier: a) Add CRC tothe transport block, b) Code block segmentation and code block CRCattachment, c) Channel coding of data and control information, d) Ratematching, e) Code block concatenation. f) Multiplexing of data andcontrol information, g) Channel interleaver, h) Error detection may beprovided on UL-SCH (uplink shared channel) transport block(s) through aCyclic Redundancy Check (CRC), and/or the like. Transport block(s) maybe used to calculate CRC parity bits. Code block(s) may be delivered tochannel coding block(s). Code block(s) may be individually turboencoded. Turbo coded block(s) may be delivered to rate matchingblock(s).

Physical uplink control channel(s) (PUCCH) may carry uplink controlinformation. Simultaneous transmission of PUCCH and PUSCH from the sameUE may be supported if enabled by higher layers. For a type 2 framestructure, the PUCCH may not be transmitted in the UpPTS field. PUCCHmay use one resource block in each of the two slots in a subframe.Resources allocated to UE and PUCCH configuration(s) may be transmittedvia control messages. PUCCH may comprise: a) positive and negativeacknowledgements for data packets transmitted at least one downlinkcarrier, b) channel state information for at least one downlink carrier,c) scheduling request, and/or the like.

According to some of the various aspects of embodiments, controlmessage(s) or control packet(s) may be scheduled for transmission in aphysical downlink shared channel (PDSCH) and/or physical uplink sharedchannel PUSCH. PDSCH and PUSCH may carry control and datamessage(s)/packet(s). Control message(s) and/or packet(s) may beprocessed before transmission. For example, the control message(s)and/or packet(s) may be fragmented or multiplexed before transmission. Acontrol message in an upper layer may be processed as a data packet inthe MAC or physical layer. For example, system information block(s) aswell as data traffic may be scheduled for transmission in PDSCH. Datapacket(s) may be encrypted packets.

According to some of the various aspects of embodiments, data packet(s)may be encrypted before transmission to secure packet(s) from unwantedreceiver(s). Desired recipient(s) may be able to decrypt the packet(s).A first plurality of data packet(s) and/or a second plurality of datapacket(s) may be encrypted using an encryption key and at least oneparameter that may change substantially rapidly over time. Theencryption mechanism may provide a transmission that may not be easilyeavesdropped by unwanted receivers. The encryption mechanism may includeadditional parameter(s) in an encryption module that changessubstantially rapidly in time to enhance the security mechanism. Examplevarying parameter(s) may comprise various types of system counter(s),such as system frame number. Substantially rapidly may for example implychanging on a per subframe, frame, or group of subframes basis.Encryption may be provided by a PDCP layer between the transmitter andreceiver, and/or may be provided by the application layer. Additionaloverhead added to packet(s) by lower layers such as RLC, MAC, and/orPhysical layer may not be encrypted before transmission. In thereceiver, the plurality of encrypted data packet(s) may be decryptedusing a first decryption key and at least one first parameter. Theplurality of data packet(s) may be decrypted using an additionalparameter that changes substantially rapidly over time.

According to some of the various aspects of embodiments, a wirelessdevice may be preconfigured with one or more carriers. When the wirelessdevice is configured with more than one carrier, the base station and/orwireless device may activate and/or deactivate the configured carriers.One of the carriers (the primary carrier) may always be activated. Othercarriers may be deactivated by default and/or may be activated by a basestation when needed. A base station may activate and deactivate carriersby sending an activation/deactivation MAC control element. Furthermore,the UE may maintain a carrier deactivation timer per configured carrierand deactivate the associated carrier upon its expiry. The same initialtimer value may apply to instance(s) of the carrier deactivation timer.The initial value of the timer may be configured by a network. Theconfigured carriers (unless the primary carrier) may be initiallydeactivated upon addition and after a handover.

According to some of the various aspects of embodiments, if a wirelessdevice receives an activation/deactivation MAC control elementactivating the carrier, the wireless device may activate the carrier,and/or may apply normal carrier operation including: sounding referencesignal transmissions on the carrier, CQI (channel qualityindicator)/PMI(precoding matrix indicator)/RI(ranking indicator)reporting for the carrier, PDCCH monitoring on the carrier, PDCCHmonitoring for the carrier, start or restart the carrier deactivationtimer associated with the carrier, and/or the like. If the devicereceives an activation/deactivation MAC control element deactivating thecarrier, and/or if the carrier deactivation timer associated with theactivated carrier expires, the base station or device may deactivate thecarrier, and may stop the carrier deactivation timer associated with thecarrier, and/or may flush HARQ buffers associated with the carrier.

If PDCCH on a carrier scheduling the activated carrier indicates anuplink grant or a downlink assignment for the activated carrier, thedevice may restart the carrier deactivation timer associated with thecarrier. When a carrier is deactivated, the wireless device may nottransmit SRS (sounding reference signal) for the carrier, may not reportCQI/PMI/RI for the carrier, may not transmit on UL-SCH for the carrier,may not monitor the PDCCH on the carrier, and/or may not monitor thePDCCH for the carrier.

A process to assign subcarriers to data packets may be executed by a MAClayer scheduler. The decision on assigning subcarriers to a packet maybe made based on data packet size, resources required for transmissionof data packets (number of radio resource blocks), modulation and codingassigned to data packet(s), QoS required by the data packets (i.e. QoSparameters assigned to data packet bearer), the service class of asubscriber receiving the data packet, or subscriber device capability, acombination of the above, and/or the like.

According to some of the various aspects of embodiments, packets may bereferred to service data units and/or protocols data units at Layer 1,Layer 2 and/or Layer 3 of the communications network. Layer 2 in an LTEnetwork may include three sub-layers: PDCP sub-layer, RLC sub-layer, andMAC sub-layer. A layer 2 packet may be a PDCP packet, an RLC packet or aMAC layer packet. Layer 3 in an LTE network may be Internet Protocol(IP) layer, and a layer 3 packet may be an IP data packet. Packets maybe transmitted and received via an air interface physical layer. Apacket at the physical layer may be called a transport block. Many ofthe various embodiments may be implemented at one or many differentcommunication network layers. For example, some of the actions may beexecuted by the PDCP layer and some others by the MAC layer.

According to some of the various aspects of embodiments, subcarriersand/or resource blocks may comprise a plurality of physical subcarriersand/or resource blocks. In another example embodiment, subcarriers maybe a plurality of virtual and/or logical subcarriers and/or resourceblocks.

According to some of the various aspects of embodiments, a radio bearermay be a GBR (guaranteed bit rate) bearer and/or a non-GBR bearer. A GBRand/or guaranteed bit rate bearer may be employed for transfer ofreal-time packets, and/or a non-GBR bearer may be used for transfer ofnon-real-time packets. The non-GBR bearer may be assigned a plurality ofattributes including: a scheduling priority, an allocation and retentionpriority, a portable device aggregate maximum bit rate, and/or the like.These parameters may be used by the scheduler in scheduling non-GBRpackets. GBR bearers may be assigned attributes such as delay, jitter,packet loss parameters, and/or the like.

According to some of the various aspects of embodiments, subcarriers mayinclude data subcarrier symbols and pilot subcarrier symbols. Pilotsymbols may not carry user data, and may be included in the transmissionto help the receiver to perform synchronization, channel estimationand/or signal quality detection. Base stations and wireless devices(wireless receiver) may use different methods to generate and transmitpilot symbols along with information symbols.

According to some of the various aspects of embodiments, the transmitterin the disclosed embodiments of the present invention may be a wirelessdevice (also called user equipment), a base station (also calledeNodeB), a relay node transmitter, and/or the like. The receiver in thedisclosed embodiments of the present invention may be a wireless device(also called user equipment-UE), a base station (also called eNodeB), arelay node receiver, and/or the like. According to some of the variousaspects of embodiments of the present invention, layer 1 (physicallayer) may be based on OFDMA or SC-FDMA. Time may be divided intoframe(s) with fixed duration. Frame(s) may be divided into substantiallyequally sized subframes, and subframe(s) may be divided intosubstantially equally sized slot(s). A plurality of OFDM or SC-FDMAsymbol(s) may be transmitted in slot(s). OFDMA or SC-FDMA symbol(s) maybe grouped into resource block(s). A scheduler may assign resource(s) inresource block unit(s), and/or a group of resource block unit(s).Physical resource block(s) may be resources in the physical layer, andlogical resource block(s) may be resource block(s) used by the MAClayer. Similar to virtual and physical subcarriers, resource block(s)may be mapped from logical to physical resource block(s). Logicalresource block(s) may be contiguous, but corresponding physical resourceblock(s) may be non-contiguous. Some of the various embodiments of thepresent invention may be implemented at the physical or logical resourceblock level(s).

According to some of the various aspects of embodiments, layer 2transmission may include PDCP (packet data convergence protocol), RLC(radio link control), MAC (media access control) sub-layers, and/or thelike. MAC may be responsible for the multiplexing and mapping of logicalchannels to transport channels and vice versa. A MAC layer may performchannel mapping, scheduling, random access channel procedures, uplinktiming maintenance, and/or the like.

According to some of the various aspects of embodiments, the MAC layermay map logical channel(s) carrying RLC PDUs (packet data unit) totransport channel(s). For transmission, multiple SDUs (service dataunit) from logical channel(s) may be mapped to the Transport Block (TB)to be sent over transport channel(s). For reception, TBs from transportchannel(s) may be demultiplexed and assigned to corresponding logicalchannel(s). The MAC layer may perform scheduling related function(s) inboth the uplink and downlink and thus may be responsible for transportformat selection associated with transport channel(s). This may includeHARQ functionality. Since scheduling may be done at the base station,the MAC layer may be responsible for reporting scheduling relatedinformation such as UE (user equipment or wireless device) bufferoccupancy and power headroom. It may also handle prioritization fromboth an inter-UE and intra-UE logical channel perspective. MAC may alsobe responsible for random access procedure(s) for the uplink that may beperformed following either a contention and non-contention basedprocess. UE may need to maintain timing synchronization with cell(s).The MAC layer may perform procedure(s) for periodic synchronization.

According to some of the various aspects of embodiments, the MAC layermay be responsible for the mapping of multiple logical channel(s) totransport channel(s) during transmission(s), and demultiplexing andmapping of transport channel data to logical channel(s) duringreception. A MAC PDU may include of a header that describes the formatof the PDU itself, which may include control element(s), SDUs, Padding,and/or the like. The header may be composed of multiple sub-headers, onefor constituent part(s) of the MAC PDU. The MAC may also operate in atransparent mode, where no header may be pre-pended to the PDU.Activation command(s) may be inserted into packet(s) using a MAC controlelement.

According to some of the various aspects of embodiments, the MAC layerin some wireless device(s) may report buffer size(s) of either a singleLogical Channel Group (LCG) or a group of LCGs to a base station. An LCGmay be a group of logical channels identified by an LCG ID. The mappingof logical channel(s) to LCG may be set up during radio configuration.Buffer status report(s) may be used by a MAC scheduler to assign radioresources for packet transmission from wireless device(s). HARQ and ARQprocesses may be used for packet retransmission to enhance thereliability of radio transmission and reduce the overall probability ofpacket loss.

According to some of the various aspects of embodiments, an RLCsub-layer may control the applicability and functionality of errorcorrection, concatenation, segmentation, re-segmentation, duplicatedetection, in-sequence delivery, and/or the like. Other functions of RLCmay include protocol error detection and recovery, and/or SDU discard.The RLC sub-layer may receive data from upper layer radio bearer(s)(signaling and data) called service data unit(s) (SDU). The transmissionentities in the RLC layer may convert RLC SDUs to RLC PDU afterperforming functions such as segmentation, concatenation, adding RLCheader(s), and/or the like. In the other direction, receiving entitiesmay receive RLC PDUs from the MAC layer. After performing reordering,the PDUs may be assembled back into RLC SDUs and delivered to the upperlayer. RLC interaction with a MAC layer may include: a) data transferfor uplink and downlink through logical channel(s); b) MAC notifies RLCwhen a transmission opportunity becomes available, including the size oftotal number of RLC PDUs that may be transmitted in the currenttransmission opportunity, and/or c) the MAC entity at the transmittermay inform RLC at the transmitter of HARQ transmission failure.

According to some of the various aspects of embodiments, PDCP (packetdata convergence protocol) may comprise a layer 2 sub-layer on top ofRLC sub-layer. The PDCP may be responsible for a multitude of functions.First, the PDCP layer may transfer user plane and control plane data toand from upper layer(s). PDCP layer may receive SDUs from upper layer(s)and may send PDUs to the lower layer(s). In other direction, PDCP layermay receive PDUs from the lower layer(s) and may send SDUs to upperlayer(s). Second, the PDCP may be responsible for security functions. Itmay apply ciphering (encryption) for user and control plane bearers, ifconfigured. It may also perform integrity protection for control planebearer(s), if configured. Third, the PDCP may perform header compressionservice(s) to improve the efficiency of over the air transmission. Theheader compression may be based on robust header compression (ROHC).ROHC may be performed on VOIP packets. Fourth, the PDCP may beresponsible for in-order delivery of packet(s) and duplicate detectionservice(s) to upper layer(s) after handover(s). After handover, thesource base station may transfer unacknowledged packet(s)s to targetbase station when operating in RLC acknowledged mode (AM). The targetbase station may forward packet(s)s received from the source basestation to the UE (user equipment).

In this specification, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” In this specification,the term “may” is to be interpreted as “may, for example,” In otherwords, the term “may” is indicative that the phrase following the term“may” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.If A and B are sets and every element of A is also an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software in combination with hardware,firmware, wetware (i.e hardware with a biological element) or acombination thereof, all of which are behaviorally equivalent. Forexample, modules may be implemented as a software routine written in acomputer language configured to be executed by a hardware machine (suchas C, C++, Fortran, Java, Basic, Matlab or the like) or amodeling/simulation program such as Simulink, Stateflow, GNU Octave, orLab VIEWMathScript. Additionally, it may be possible to implementmodules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++ or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. Finally, it needs to beemphasized that the above mentioned technologies are often used incombination to achieve the result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)using FDD communication systems. However, one skilled in the art willrecognize that embodiments of the invention may also be implemented inTDD communication systems. The disclosed methods and systems may beimplemented in wireless or wireline systems. The features of variousembodiments presented in this invention may be combined. One or manyfeatures (method or system) of one embodiment may be implemented inother embodiments. Only a limited number of example combinations areshown to indicate to one skilled in the art the possibility of featuresthat may be combined in various embodiments to create enhancedtransmission and reception systems and methods.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112, paragraph 6. Claims that do not expressly include the phrase“means for” or “step for” are not to be interpreted under 35 U.S.C. 112,paragraph 6.

What is claimed is:
 1. A method comprising: a) receiving, by a wirelessdevice, at least one control message from a first base station, said atleast one control message causing configuration of measurementparameters of said wireless device, said configuration triggeringmeasurements of channel state information corresponding to a subset ofcarriers, said at least one control message causes configuration of: i)a channel state information transmission period; ii) a channel stateinformation transmission resource; iii) a channel state informationmeasurement resource; iv) a physical uplink control channel format; andv) a list of carriers for said measurement of channel state information,carriers in said list of carriers belonging to at least two basestations or belonging to at least two sectors of said first basestation; b) measuring, by said wireless device, said channel stateinformation for each active carrier in said list of carriers on aplurality of OFDM subcarriers and a first plurality of subframesdetermined by a measurement resource based on said configuration; c)multiplexing and encoding said channel state measurement informationbased on said physical uplink control channel format; d) spreading bymultiplying said multiplexed and encoded information by a sequencegenerated in said wireless device; e) transmitting said spreadinformation employing single-carrier OFDM transmission on said channelstate information transmission resource according to said channel stateinformation transmission period; and f) simultaneously receiving signalsfrom a subset of active carriers in said list of carriers, said signalscarrying a plurality of data packets for said wireless device, carriersin said subset of carriers belonging to said at least two base stationsor belonging to at least two sectors of said first base station.
 2. Themethod of claim 1, wherein said measurement resource determines aplurality of subframes that are object of said channel state informationmeasurement.
 3. The method of claim 1, wherein said channel stateinformation is quantized separately, by said wireless device, fordifferent active carriers in said list of carriers.
 4. The method ofclaim 1, wherein said channel state information is quantized jointly, bysaid wireless device, across active carriers in said list of carriers.5. The method of claim 1, wherein said channel state information isrepresented, by said wireless device, by a product of a first channelstate information matrix and a second channel state information matrix.6. The method of claim 5, wherein said first channel state informationmatrix is global channel state information and comprises jointinformation about all active carriers in said list of carriers.
 7. Themethod of claim 5, wherein said second channel state information matrixis local channel state information and comprises separate informationabout different active carriers in said list of carriers.
 8. The methodof claim 5, wherein said first channel state information matrixcomprises information about channel eigen values.
 9. The method of claim5, wherein said second channel state information matrix comprisesinformation about channel eigen vectors.
 10. The method of claim 5,wherein said first channel state information matrix is left multipliedby said second channel state information matrix.
 11. The method of claim5, wherein said first channel state information matrix is rightmultiplied by said second channel state information matrix.
 12. Themethod of claim 1, wherein said channel state information is quantizedusing a multiple description code.
 13. The method of claim 12, whereinsaid channel state information is transmitted over a plurality ofseparate instances of said physical uplink control channel.
 14. Themethod of claim 13, wherein each instance in said plurality of separateinstances of said physical uplink control channel carries coarse channelstate information.
 15. The method of claim 1, wherein said channel stateinformation is encoded jointly across active carriers in said subset ofcarriers.
 16. The method of claim 1, wherein said channel stateinformation for active carriers other than a primary carrier of saidwireless device is encoded differentially with respect to said channelstate information for said primary carrier of said wireless device. 17.The method of claim 1, wherein said sequence is determined based on atemporary identifier assigned to said wireless device by a base station.18. A wireless device comprising: a) one or more communicationinterfaces to communicate with a first base station; b) one or moreprocessors; and c) memory storing instructions that, when executed bysaid one or more processors, perform the following: i) receive at leastone control message from said first base station via said one or morecommunication interfaces, said at least one control message causingconfiguration of measurement parameters of said wireless device, saidconfiguration triggering measurements of channel state informationcorresponding to a subset of carriers, said at least one control messagecauses configuration of: (1) an uplink transmission resource; (2)physical uplink channel format; and (3) a list of carriers for saidmeasurement of channel state information, carriers in said list ofcarriers belonging to at least two base stations or belonging to atleast two sectors of said first base station; ii) measure said channelstate information for each active carrier in said list of carriers basedon said configuration; iii) multiplex and encode said channel statemeasurement information based on said physical uplink channel format;iv) transmit said information employing single-carrier OFDM transmissionon said uplink transmission resource; and v) simultaneously receivesignals from a subset of carriers in said list of carriers, said signalscarrying a plurality of data packets for said wireless device, carriersin said subset of carriers belonging to said at least two base stationsor belonging to at least two sectors of said first base station.
 19. Thewireless device of claim 18, wherein said instructions, when executed bysaid one or more processors, encode said channel state informationjointly across said subset of carriers.
 20. The wireless device of claim18, wherein said instructions, when executed by said one or moreprocessors, quantize said channel state information jointly across saidlist of carriers.